doctor_ratz

I just put in a new 540 cube big block to replace one of a pair that was blown. I bought a new block w/o any plugs or bypass valves installed. After assembly, and install, I noticed on another engine that there are two by-pass valves. One under the filter, and one up under the threaded nipple for the filter. That's when the panic set in. I did not install that bypass valve under the nipple, only the one in the filter area. I have oil pressure on the gauge. Do I need to pull the engine and install the second bypass ?????
I have been told that this second bypass is only for truck type oil coolers. Which is correct ?????

getrdunn

iTrader: (7)

I'm not running any in my 496's. I know things have changed over the years however I never recall ever seeing any there. Will be interesting to see what others have or are doing. If you don't get a response do a quick google search. I can't understand why there would be two. What kind of block is it?

dennis r

iTrader: (1)

you should block off the one under the filter housing so all the oil goes thru the filter and cooler

getrdunn

iTrader: (7)

Seems like a nickel works perfect for that if I remember right.

Rockfish71

Sure if it is worth 5 cents to you me I would tap it to 3/8 and plug it

doctor_ratz

These are 502 genVI blocks.
I just checked the damaged block and it does not have the second bypass valve under the nipple.
The reason you should not completely plug the bypass under the filter is for possible oil stavation if your cooler or filter get plugged. There is a 30 PSI bypass available from GM performance to replace the standard 15 psi automotive unit. I am an old drag racer and have had trouble in the past losing oil pressure with a blocked bypass on small blocks.

doctor_ratz

Did a search, and you guys were right. Seems like the correct answer is no by pass in the nipple, and plug the one on the oil filter pad. If I can do it in the boat, that is what I am going to do, other wise it will have to wait till winter.
Thanks guys !!!!!!!!!!!!!

jeffswav

Yea, remove the center valve and plug or install a 30psi vave in the one on the side.

dogturd21

I am only slightly familier with this issue, but the question in my mind is: if the valves are incorrect, can this be fixed without removing the engine ?

getrdunn

iTrader: (7)

I had to look twice and chuckle a bit when I saw a reputable speed shop doing it downstate.